Gear-shaping attachment for watch-makers  lathes



(No Model.)

B. RIVETT.

GEAR SHAPING- ATTACHMENT FOR WATCH MAKERS LATHES.

No. 389,905. Patented Sept. 25, 1888.

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iEjNiTED STATES PATENT (Eri rea.

EDW'ARD RIVETT, OF BOSTON, MASSACHUSETTS.

GEAR-SHAPING ATTACHMENT FOR WATCH-MAKERS LATHES.

SPECIFICATION forming part of Letters Patent N0. 389,905, dated September 25, 1888.

Application filed February 11, 1888. Serial No. 363,668.

To all whom it may concern.-

Be it known that I, EDWARD Rrvn'rr, a citizen of the United States, and a resident of Boston, in the county of Suffolk and State of Massachusetts, have invented new and useful Improvements in Rounding Attachments for Watch-Makers Lathe's,of which the following, taken in connection with the accompanying drawings, is a specification.

This invention relates to improvements in rounding-machines for the purpose of rounding or truing up watchwheels; and the invention consists of an attachment to an ordinary watch-makers lathe by means of which such rounding operation can be easily accomplished without the need of an entire special machine or device for this purpose.

The invention is carried out as follows, reference being had to the accompanying drawings, wherein Figure 1 represents a front elevation of an ordinary watch-makers lathe provided with my improved rounding attachment. Fig. 2 represents a horizontal section on the line A B, shown in Fig. 1. Fig. 3 represents a vertical cross-section on the line C D, also shown in Fig. 1; and Fig. 4 represents ahorizontal section on the line E F, shown in Figs. 1 and 3.

Similar letters refer to similar parts wherever they occur on the different parts of the drawings.

a represents the bed of an ordinary watchmakers lathe, on which bis the head-stock, in bearings in which is journaled the spindle c,provided with the conepulley c,in the ordinary manner. To the forward end of the spindle c, I secure in a suitable manner a spiral cutter, c, of the kind usually employed in rounding-machines.

My improved rounding attachment is constructed and operated as follows:

(1 is the frame of the attachment, the base or under side of which is preferably provided with guide-lips d (1, adapted to fit on the ad justable tool-holder plate 6, which latter is provided with guide-lips e e, as usual, fitting against the side edges of the bed a, as is common in watch-makers lathes. In the base of the frame (Z is made a T-headed slot or groove, d, adapted to receive the correspondinglyshaped head of the fastening-bolt f, that passes through the plate e and through a slot, at, in

(No model.)

the bed-plate a, and is provided with athnmb nnt,f, below the bed a, as shown in Figs. 1 and 3. It will thus be seen that by thisarrangement the frame (2 may be adjusted in the direction of the axis of the cutterspindle c and at a right angle thereto, as may be desired, according to the diameter of the wheel to be cut or rounded, and after being so adjusted it is secured firmly to the bed a simply by tightening the nutf below the bed a.

In horizontal guides (Z (Z in the side of the frame (Z is adjustable to and from the cutter c the wheel-carrying block 9, provided with lower and upper wheel centering-spindles, g and 9, arranged in a vertical position and in a line centrally with each other, as shown in Figs. 1 and 3. The said spindles are adjustable up and down in cylindrical bores made in the lower and upper parts of the Wheel-carrying block 9, and are secured in position with the Wheel G to be cut or rounded, journaled, and held between their ends by means of the regulating set-screws G and G. (Shown in Fig. 1)

To the top of the frame (I is firmly secured the hardened-steel rest'plate ii, that serves as a support for the wheel Gwhile the latter is being cut or rounded by the cutter c", said restplate having a slotted perforation, h, made through it for the reception of the lower wheel centering or carrying spindle, g, as shown in Figs. 2 and 3, and thus permitting said spindle, the upperspindle, the wheel held by them, and the wheel-carrying block 9 to be moved to and from the cutter cduring the operation of moving the wheel G to or from the cutter 0".

The block 9 is moved to and from the cutter c by the following mechanism, viz:

7c is a hand-lever pivoted at k to the rear of the wheel-earrying block 9, as shown in Fig. 3. The lower end of the lever k is pivoted to the frame d by means of the link it, and it will thus be seen that by swinging the said lever 7- forward and back the block 5 is moved to and from the cutter c".

For the purpose of limiting the forward motion of the block 5 and the wheel G, held by its centering-spindles g so as to obtain the desired depth of cut of the teeth of the wheel under operation, I employ a horizontal adjustable set-serew, D, screwed through the frame d, combined with a screw or stop projection, 9 secured to the Wheel-carrying block 9, as

shown in Fig. 4. By adjusting the position of the set-screw D it will be seen that the wheelcarrying block 9 will be limited in its forward motion toward the cutter c, for the purpose as above set forth. The wheel G to be cut or rounded is so held and journaled between the ends of the spindles or centers gg that it is free to turn around its axis during the operation of cutting or rounding its teeth.

Small wheels for watches and similar fine movements are generally first cut on a gearcutting machine,wherc they are made approximately true; but to obtain a perfect runninggcar it is essential that it should afterward be rounded or trued up, and for this purposeI use my improved machine and proceed as follows: A fter having adjusted thepositiou of the frame d relative to the cutter c", I journal the gear G to be rounded between the spindles or centers {1' gin such a manner that it is supported on the rest-plate h, as shown in Fig. 3. I now regulate the position of the set-screw D so thatthe forward motion of the wheel-earrying block gshall be limited according to the depth of the teeth desired to be cutby the cutter c on the wheel G. The cutter c is then set in a quick rotary motion around its axis and the wheel G- brought up against it by pressing and holding the lever 7a in its forward position, as shown in Figs. 3 and 4, thus causing the spiral cutter c to round or even the teeth of the wheel G and to turn the latter around its axis until the whole circunr ference of the wheel is cut or rounded, when it and the block 9 are withdrawn, the new fin ished wheel removed, and another one put in its place, and so on.

and its vertically-adjustable centering-spin- I dles g g", substantially as and for the purpose set forth.

2. The frame (Z, having the slotted wheel rest It secured to it, combined with the horizontally-adjustable wheel-carrying block g, its centering spindles gg, and the adjustable stop-screw D for limiting the forward motion of the block 9, as and for the purpose set forth.

3. The frame (Z and its slotted wheel-rest h, as described, combined with the adjustable block {1 and its centering-spindles gg, and the lever is, pivoted to the frame d and block 9, substantially as and for the purpose set forth.

t. The frame (I and its slotted wheel-rest h, and the wheelcarrying block 9, adapted to slide on said frame (I, and having means for holding the wheel to be cut, as described, in combination with the shoe (1, adj ustably secured to the bed a, and the headstock b, with its rotary spindle c and spiral cutters, substantially as and for the purpose set forth.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, on this 8th day of February, A. D. 1888.

ED \VARD PIVETT.

\Vitnesses:

ALBAN ANDREN, HENRY CHADBOURN. 

